Re: Crashes/hung tasks with z3pool under memory pressure

[Guenter Roeck]

On Tue, Apr 17, 2018 at 12:14:37AM +0200, Vitaly Wool wrote:
[ ... ]
> Ugh. Could you please keep that patch and apply this on top:
> 
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index c0bca6153b95..e8a80d044d9e 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -840,6 +840,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
>  			kref_get(&zhdr->refcount);
>  			list_del_init(&zhdr->buddy);
>  			zhdr->cpu = -1;
> +			break;
>  		}
>  		list_del_init(&page->lru);
> 
Much better, in a way. The system now takes much longer to crash,
and the crash reason is a bit different. The log is too long to attach,
so I copied it to [1].

crashdump.0002			Latest log
000[12]-Fix-attempt-[12].patch	Patches applied on top of v4.17.0-rc1.

Hope it helps,
Guenter


[1] http://server.roeck-us.net/qemu/z3pool/